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Fanggao Chang

Bio: Fanggao Chang is an academic researcher from Henan Normal University. The author has contributed to research in topics: Crystal structure & Dielectric. The author has an hindex of 1, co-authored 1 publications receiving 12 citations.

Papers
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Journal ArticleDOI
Gui lin Song1, Jian Su1, Haigang Yang1, Na Zhang1, Fanggao Chang1 
TL;DR: In this paper, a study on the influence of Ca2+ doping on the structure, dielectric, and ferromagnetic properties of BiFeO3 ceramics was conducted.
Abstract: This paper deals with the preparation of multiferroic Bi1−x Ca x FeO3(x = 0–0.2) ceramics with the sol–gel method and a study on the influence of Ca2+ doping on the structure, dielectric, and ferromagnetic properties of BiFeO3 ceramics. The result shows that the XRD analysis reveals a phase transition in Ca-doped BiFeO3 from rhombohedral to orthorhombic when x is greater than 0.1. The dielectric constant (e r) of Bi0.9Ca0.1FeO3 measured at 1 kHz is about seven times greater than that of BiFeO3, and Bi0.8Ca0.2FeO3 is less than one-tenth of BiFeO3. It might be understood in terms of the dipole polarization, oxygen vacancy and lattice phase transition. Magnetic measurements show that the M-H of Bi1 − x Ca x FeO3 samples exhibit unsaturated and symmetric magnetic hysteresis loops with the increase of Ca2+, indicating the weakly ferromagnetic behavior. It indicates that there is coexistence of Fe2+ and Fe3+ in Bi1 − x Ca x FeO3 samples according to the XPS spectrum. The ratio of Fe2+/Fe3+ increases with doping Ca2+ content and the magnetic properties of BiFeO3 are enhanced. It is evident that the ferromagnetic phase transition of BiFeO3 samples occurs at 878 K by measuring the M–T and DSC curves. The T N of BiFeO3 will be reduced from 644 to 638 K and the T M does not change slightly at 878 K with increasing Ca2+ content. T N and T M of Bi1 − x Ca x FeO3 change depends mainly on the magnetic structure of relative stability and Fe–O–Fe super-exchange strength.

14 citations


Cited by
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Journal ArticleDOI
TL;DR: The polycrystalline 0.75BiFeO3−0.25BaTiO3 and 0.05 TiO3 ceramics are successfully prepared by solid state reaction method as mentioned in this paper.

30 citations

Journal ArticleDOI
TL;DR: In this article, the effect of Ca2+ substitution on the grain size of BCFO ceramics sintered at 1250°C for 2 1/h was investigated.

20 citations

Journal ArticleDOI
TL;DR: In this article, the structural, magnetic, dielectric and impedance properties of the Sm1-xBixFe1-yMnyO3 [SFO], Sm0.9Bi0.1FeO3 (SBFO), Sm 0.9Mn0.

13 citations

Journal ArticleDOI
G.L. Song1, J. Su1, S.K. Fang1, J.S. Tong1, Xiaopei Xu1, Yang Feng1, Na Zhang1, F.G. Chang1 
TL;DR: In this article, the crystal structural, dielectric, ferromagnetic properties and high temperature magnetic phase transition of Sm1-xCaxFeO3 (x = 0.0-0.3) by the conventional solid-state reaction method were investigated.

12 citations

Journal ArticleDOI
TL;DR: In this article, the BixLa1−xMnO3+δ solid solutions were synthesized using sol-gel combustion method with citric acid as a fuel and complexing agent.
Abstract: In this study, the BixLa1−xMnO3+δ solid solutions (x from 0 to 0.65) were synthesized using sol–gel combustion method with citric acid as a fuel and complexing agent. It was shown that changes in chemical composition of the materials lead to the evolution of crystal structure, morphology, and magnetic properties. The thermal behavior of precursor gel was investigated by thermogravimetric and differential scanning calorimetry (TG-DSC) measurements. X-ray diffraction (XRD) analysis demonstrated that all samples were monophasic. The Rietveld analysis showed that the structure can be indexed by trigonal or cubic unit cell depending on Bi3+ content. Scanning electron microscopy (SEM) was used to evaluate morphological features of the synthesized materials and revealed that Bi3+ ions significantly promote growth of the grains. The sol–gel-derived BixLa1−xMnO3+δ specimens were also characterized by FT-IR spectroscopy and magnetization measurements, which showed a clear correlation between magnetic properties and crystal structure of the materials.

8 citations